Department of Chemistry, The Scripps Research Institute , 10550 N. Torrey Pines Road, La Jolla, California 92037, United States.
Department of Chemistry, University of Pittsburgh , 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States.
J Am Chem Soc. 2017 Nov 8;139(44):15576-15579. doi: 10.1021/jacs.7b08383. Epub 2017 Oct 26.
Removable tridentate directing groups inspired by pincer ligands have been designed to stabilize otherwise kinetically and thermodynamically disfavored 6-membered alkyl palladacycle intermediates. This family of directing groups enables regioselective remote hydrocarbofunctionalization of several synthetically useful alkene-containing substrate classes, including 4-pentenoic acids, allylic alcohols, homoallyl amines, and bis-homoallylamines, under Pd(II) catalysis. In conjunction with previous findings, we demonstrate regiodivergent hydrofunctionalization of 3-butenoic acid derivatives to afford either Markovnikov or anti-Markovnikov addition products depending on directing group choice. Preliminary mechanistic and computational data are presented to support the proposed catalytic cycle.
受夹钳配体启发的可移除的三叉型导向基团被设计用来稳定 otherwise kinetically and thermodynamically disfavored 6-membered alkyl palladacycle intermediates。这类导向基团能够在 Pd(II)催化下对几种具有合成用途的含烯烃底物类别进行区域选择性远程碳氢官能化，包括 4-戊烯酸、烯丙醇、偕胺和双偕胺。结合之前的研究结果，我们展示了 3-丁烯酸衍生物的区域发散性氢官能化，根据导向基团的选择，可以得到 Markovnikov 或反 Markovnikov 加成产物。本文提出了初步的机理和计算数据来支持所提出的催化循环。
